\begin{tikzpicture}
	\node (obj) [bluebox]                {Binary object};
	\node (skc) [apribox,  below=of obj] {skconfig};
	\node (xml) [greenbox, below=of skc] {XML specification};

	\draw[arrow] (obj) to (skc);
	\draw[arrow] (skc) to (xml);
\end{tikzpicture}
